The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
Gene Review

bam  -  bag of marbles

Drosophila melanogaster

Synonyms: BAM, Bam, Bam-C, BamC, BamF, ...
Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

High impact information on bam

  • An apparent null mutation causes abnormal cysts to form containing an excess number of cells that cannot differentiate into gametes. bam function resides within a simple 2.2-kb transcription unit encoding a single 442-amino-acid protein that shows similarity to the product of the ovarian tumor gene [1].
  • The specific expression of bam RNA within female cystoblasts suggested that it might be involved in the specific cell-cycle alterations that occur during cystocyte divisions [1].
  • bag-of-marbles: a Drosophila gene required to initiate both male and female gametogenesis [1].
  • We have shown that bam(-) GSCs can be maintained and promoted to divide in vitro in media containing Dpp [2].
  • By using this approach, we demonstrate that bam- cells can populate the gonad and become established as germ-line stem cells [3].

Biological context of bam


Anatomical context of bam

  • Taken together, our results suggest that bam and bgcn regulate progression through the male germline stem cell lineage by cell-intrinsically restricting the proliferation of amplifying germ cells [4].
  • The niche for germline stem cells (GSCs) provides a Dpp/Bmp signal, which is essential for GSC maintenance. bam is both necessary and sufficient for the differentiation of immediate GSC daughters, cystoblasts [8].
  • Tumor cells containing the wild-type bam gene under heat shock transcriptional control are able to produce functional oocytes [3].
  • This study demonstrates that Bmp signals from the somatic cells maintain GSCs, at least in part, by repressing bam expression in the Drosophila testis. dpp signaling is known to be essential for maintaining GSCs in the Drosophila ovary [9].
  • alpha- and beta-Spectrin are major components of a submembrane cytoskeletal network connecting actin filaments to integral plasma membrane proteins [10].

Physical interactions of bam

  • Finally, we show that Med and Mad directly bind to the bam silencer in vitro [8].
  • These results suggest that RBP9 protein binds to bam mRNA to down regulate BAM protein expression, which is essential for the initiation of cystocyte differentiation into functional egg chambers [11].

Regulatory relationships of bam

  • Also, mutations in bgcn dominantly enhance a bam mutant phenotype, further corroborating the interdependence of these two genes' functions [12].
  • We demonstrate that one function of Bam is to block Dpp signaling downstream of Dpp receptor activation, thus establishing the existence of a negative feedback loop between the action of the two genes [13].
  • Gbb/Bmp signaling is essential for maintaining germline stem cells and for repressing bam transcription in the Drosophila testis [9].
  • Pelota controls self-renewal of germline stem cells by repressing a Bam-independent differentiation pathway [14].
  • RBP9 appears to stimulate cystocyte differentiation by regulating the expression of bag-of-marbles (bam) mRNA, which encodes a developmental regulator of germ cells [11].

Other interactions of bam

  • We demonstrate that Piwi and Bam proteins are expressed independently of each other in reciprocal patterns in GSCs and cystoblasts [15].
  • Finally, pum is epistatic to bam, indicating that niche Piwi does not regulate Bam-C through Pum [15].
  • Here we investigate how bam and bgcn regulate the male germline stem cell lineage [4].
  • The expression of phosphorylated Mad (pMad), a Bmp signaling indicator, is restricted to GSCs and some cystoblasts, which have repressed bam expression [8].
  • In marked GSCs mutant for Med and punt, two essential Bmp signal transducers, bam transcription is also elevated [8].

Analytical, diagnostic and therapeutic context of bam


  1. bag-of-marbles: a Drosophila gene required to initiate both male and female gametogenesis. McKearin, D.M., Spradling, A.C. Genes Dev. (1990) [Pubmed]
  2. Establishment of stable cell lines of Drosophila germ-line stem cells. Niki, Y., Yamaguchi, T., Mahowald, A.P. Proc. Natl. Acad. Sci. U.S.A. (2006) [Pubmed]
  3. Ovarian cystocytes can repopulate the embryonic germ line and produce functional gametes. Niki, Y., Mahowald, A.P. Proc. Natl. Acad. Sci. U.S.A. (2003) [Pubmed]
  4. bag-of-marbles and benign gonial cell neoplasm act in the germline to restrict proliferation during Drosophila spermatogenesis. Gönczy, P., Matunis, E., DiNardo, S. Development (1997) [Pubmed]
  5. Localization and function of Bam protein require the benign gonial cell neoplasm gene product. Lavoie, C.A., Ohlstein, B., McKearin, D.M. Dev. Biol. (1999) [Pubmed]
  6. Dpp signaling silences bam transcription directly to establish asymmetric divisions of germline stem cells. Chen, D., McKearin, D. Curr. Biol. (2003) [Pubmed]
  7. Rapid evolution and gene-specific patterns of selection for three genes of spermatogenesis in Drosophila. Civetta, A., Rajakumar, S.A., Brouwers, B., Bacik, J.P. Mol. Biol. Evol. (2006) [Pubmed]
  8. Bmp signals from niche cells directly repress transcription of a differentiation-promoting gene, bag of marbles, in germline stem cells in the Drosophila ovary. Song, X., Wong, M.D., Kawase, E., Xi, R., Ding, B.C., McCarthy, J.J., Xie, T. Development (2004) [Pubmed]
  9. Gbb/Bmp signaling is essential for maintaining germline stem cells and for repressing bam transcription in the Drosophila testis. Kawase, E., Wong, M.D., Ding, B.C., Xie, T. Development (2004) [Pubmed]
  10. {beta}-Spectrin functions independently of Ankyrin to regulate the establishment and maintenance of axon connections in the Drosophila embryonic CNS. Garbe, D.S., Das, A., Dubreuil, R.R., Bashaw, G.J. Development (2007) [Pubmed]
  11. Requirement of RBP9, a Drosophila Hu homolog, for regulation of cystocyte differentiation and oocyte determination during oogenesis. Kim-Ha, J., Kim, J., Kim, Y.J. Mol. Cell. Biol. (1999) [Pubmed]
  12. The Drosophila cystoblast differentiation factor, benign gonial cell neoplasm, is related to DExH-box proteins and interacts genetically with bag-of-marbles. Ohlstein, B., Lavoie, C.A., Vef, O., Gateff, E., McKearin, D.M. Genetics (2000) [Pubmed]
  13. Germline stem cell number in the Drosophila ovary is regulated by redundant mechanisms that control Dpp signaling. Casanueva, M.O., Ferguson, E.L. Development (2004) [Pubmed]
  14. Pelota controls self-renewal of germline stem cells by repressing a Bam-independent differentiation pathway. Xi, R., Doan, C., Liu, D., Xie, T. Development (2005) [Pubmed]
  15. Regulatory relationship among piwi, pumilio, and bag-of-marbles in Drosophila germline stem cell self-renewal and differentiation. Szakmary, A., Cox, D.N., Wang, Z., Lin, H. Curr. Biol. (2005) [Pubmed]
  16. Eucaryotic transposable genetic elements with inverted terminal repeats. Potter, S., Truett, M., Phillips, M., Maher, A. Cell (1980) [Pubmed]
WikiGenes - Universities